Five years ago today, leaders of GRAND-AM Road Racing and the American Le Mans Series shocked the racing world.

In a news conference at Daytona International Speedway, GRAND-AM Founder Jim France and President and CEO Ed Bennett joined American Le Mans Series Founder Don Panoz and ALMS President and CEO Scott Atherton to announce plans to merge the ALMS and the GRAND-AM Rolex Sports Car Series, forming a new series to begin competition in the 2014 season.

There have been highlights aplenty since that historic day. Here are five from each year since then:

2013

Four-Class Format Unveiled: Just prior to the start of the 2013 season, series officials announced there would be four classes in the new series. There have been twists and turns with each, but they’re the same four classes we still have today in the IMSA WeatherTech SportsCar Championship.

Prototype (P) – The headline class for the series would feature a mix of Daytona Prototypes from GRAND-AM and LM P2 prototypes from the ALMS. These cars would remain eligible to compete in the class through the end of the 2016 WeatherTech Championship.

GT Le Mans (GTLM) – The manufacturer-backed GT class was carried over in its entirety from the ALMS, utilizing the same technical specifications as the main GTE class at the 24 Hours of Le Mans and the FIA World Endurance Championship. This class provided the backbone for a relationship between IMSA, the FIA and the Automobile Club de l’Ouest (ACO), which organizes the 24 Hours of Le Mans. The GTLM class continues to use ACO technical rules to this day.

GT Daytona (GTD) – This class also featured a mix of cars with roots in either the Rolex Series GT class or the ALMS GT Challenge (GTC) class. These cars remained eligible to compete in the WeatherTech Championship through the end of the 2015 season.

Prototype Challenge (PC) – The Pro-Am prototype class came over in total from the ALMS, complete with its open-cockpit ORECA FLM09 chassis powered by spec-V8 engines. PC will complete its final WeatherTech Championship race in the Motul Petit Le Mans at Road Atlanta on Oct. 7.

Rolex 24 At Daytona Kicks Off Final GRAND-AM Season: Chip Ganassi Racing – the most successful Daytona Prototype team in GRAND-AM history – appropriately kicked off the final season of Rolex Series competition with a victory in the Rolex 24 At Daytona on Jan. 26-27. The foursome of sports car legend Scott Pruett, multi-time Rolex Series Champion Memo Rojas, budding IndyCar star Charlie Kimball and Juan Pablo Montoya – an Indy 500, Formula 1 and Monster Energy NASCAR Cup Series race winner – combined to take the overall victory in Ganassi’s No. 01 BMW-powered Riley DP.

The No. 24 Audi R8 fielded by Alex Job Racing and co-driven by Filipe Albuquerque, Oliver Jarvis, Edoardo Mortara and Dion von Moltke won the GT class, while the GX class – in its only Rolex Series season – was won by Nelson Canache, David Donohue, Shane Lewis and Dr. Jim Norman with the No. 16 Napleton Racing Porsche Cayman.

IMSA Reborn: Just prior to the American Le Mans Series presented by Tequila Patrón season-opening Mobil 1 Twelve Hours of Sebring Fueled by Fresh From Florida, a new name for the series and the sanctioning body were unveiled. The series would be known as “United SportsCar” – later renamed TUDOR United SportsCar Championship when TUDOR signed on as entitlement partner later in 2014. And the name for the sanctioning body? The International Motor Sports Association (IMSA), with historic roots dating back to 1969 when it was formed by John and Peggy Bishop and NASCAR founder Bill France.

Audi Swan Song Headlines Sebring ALMS Opener: The 2013 ALMS season opened with the Mobil 1 Twelve Hours of Sebring Fueled by Fresh From Florida, which included the final Sebring appearance of the breathtaking Audi R18 e-tron Quattro race car. There were a pair of Audis in the P1 class, which ran away from the rest of the field, with Marcel Fassler, Benoit Treluyer and Jarvis – on the heels of a GT win in the Rolex 24 – taking the overall victory.

Road America Hosts Historic GRAND-AM/ALMS Joint Weekend: For the only time in history, both the GRAND-AM Rolex Sports Car Series and the American Le Mans Series presented by Tequila Patrón competed on the same weekend at the same venue. It happened at Road America in Elkhart Lake, Wisconsin on the weekend of Aug. 9-10.

The Rolex Series headlined Saturday’s festivities with a two-hour, 45-minute race won overall and in the Daytona Prototype class by Brendon Hartley and Scott Mayer with Starworks Motorsport, with Bill Auberlen and Paul Dalla Lana taking the GT class win in the No. 94 Turner Motorsport BMW and Joel Miller and Tristan Nunez winning GX in the SpeedSource Mazda.

Rolex 24 At Daytona Opens New Era for North American Sports Car Racing: The opening round of the TUDOR United SportsCar Championship – the 52nd Rolex 24 At Daytona – featured a whopping, 68-car field across the four competing classes. The overall and Prototype class victory went to Joao Barbosa, Christian Fittipaldi and Sebastien Bourdais in the No. 5 Action Express Racing Corvette DP.

Brown started the race from the pole position in the No. 2 Honda prototype before giving way to co-driver van Overbeek – from nearby Oakland, California – who brought home a popular victory for the team.

IMSA at Indy: The lone IMSA race to be held to date at Indianapolis Motor Speedway happened in 2014 as part of the annual NASCAR Brickyard 400 weekend. Barbosa and Fittipaldi – on their way to a championship-winning season – claimed the victory for Action Express Racing in the No. 5 Corvette DP.

Canadian racer Chris Cumming combined with then-IndyCar racer Jack Hawksworth to win the PC class for RSR Racing, while Kuno Wittmer – also on his way to a championship – shared the GTLM victory with his No. 93 Dodge Viper co-driver, Jonathan Bomarito. Alessandro Balzan and Jeff Westphal won GTD in the No. 63 Scuderia Corsa Ferrari.

First GT-only Race at VIR a Barnburner: In what now has become an annual tradition, the first GT-only race for IMSA was held at VIRginia International Raceway. And somewhat appropriately, the racetrack with its signature barns dotting the landscape produced a barnburner of a finish.

The race came down to a last-lap battle between ex-F1 racer Giancarlo Fisichella in the No, 62 Risi Competizione Ferrari and Wolf Henzler in the No. 17 Team Falken Tire Porsche 911 RSR. Henzler had led the previous 12 laps, but coming to the checkered flag, Fisichella got a great run coming down the backstretch and zoomed past to take the victory for himself and co-driver Pierre Kaffer. Dane Cameron and Markus Palttala won in GTD in the No. 94 Turner Motorsport BMW, the third and final victory of a championship-winning season for Cameron.

Action Express Kicks Off Early IMSA Dynasty: Joao Barbosa and Christian Fittipaldi claimed their first of two consecutive Prototype season-long championships in the No. 5 Action Express Racing Corvette DP, as well as their first of three straight Tequila Patrón North American Endurance Cup titles.

Kuno Wittmer took the GTLM championship in the final season of competition for the No. 93 Dodge Viper GTS-R team, while Colin Braun and Jon Bennett won the PC title in their No. 54 CORE autosport entry and Cameron won the GTD championship with Turner Motorsport.

AXR Adds Sebring Victory: One year after teaming up to win the Rolex 24 At Daytona, Joao Barbosa, Christian Fittipaldi and Sebastien Bourdais joined forces to win another of sports car racing crown jewels, the Mobil 1 Twelve Hours of Sebring Fueled by Fresh From Florida. It was the first of two victories on the season for the trio – they also won the season-ending Petit Le Mans – which gave them the Tequila Patrón North American Endurance Cup and the season championship for the second straight year.

Winners at Le Mans: Five full-time IMSA racers claimed victories in the 24 Hours of Le Mans, headlined by overall winners Earl Bamber and Nick Tandy – who joined forces with F1 driver Nico Hulkenberg – to take the overall and LM P1 class victory in the No. 19 Porsche 919 Hybrid.

The GTE Pro class victory at Le Mans went to the trio of Tommy Milner, Oliver Gavin and Jordan Taylor in the No. 64 Corvette Racing Chevrolet Corvette C7.R. Milner and Gavin, shared the same car (which carried No. 4 in IMSA) for the full season, while Taylor’s regular ride was the No. 10 Konica Minolta Corvette DP alongside his brother, Ricky Taylor, for their father’s Wayne Taylor Racing team.

WeatherTech Signs On: One of the better-kept secrets in motorsports history was pulled off at the now-annual “State of the Sport” presentation at Road America. WeatherTech, one of the world’s leading manufacturers of automotive aftermarket products was introduced as the new entitlement partner of what would become the IMSA WeatherTech SportsCar Championship at the beginning of the 2016 season.

Wild Ending at Petit Le Mans: Torrential rains throughout the season-ending Petit Le Mans at Road Atlanta brought about a lengthy red-flag stoppage and an early checkered flag, as well as a surprise overall winner. Tandy, Pilet and Lietz – from the GTLM class – took both class and overall honors in the No. 911 Porsche.

Barbosa, Fittipaldi and Bourdais wound up third overall but won the Prototype class, which also enabled them to win both the season-long and Tequila Patrón North American Endurance Cup titles. Guasch, Kimber-Smith and Palmer earned yet another crown jewel victory in PC, while Patrick Lindsey, Pumpelly and Madison Snow took GTD class honors in the race as Sweedler and Bell claimed the season title.

2016

New GT Cars Strengthen Production-Based Classes: The 2016 WeatherTech Championship ushered in a new era of GT competition with the introduction of new technical specifications for both classes. The new specs for the GTLM class came online just as the new Ford GT, BMW M6 GTLM and Ferrari 488 made their debut.

The GTD class saw explosive growth with the adaptation of full international GT3 technical regulations. Seven different manufacturers: Audi, Ferrari, Porsche, Dodge, BMW, Lamborghini and Aston Martin competed in 2016 with all six full-time class competitors winning at least once. Aston Martin competed in three races.

0.034 Seconds: That was the margin of victory for the No. 4 Corvette Racing Chevrolet Corvette C7.R shared by Gavin, Milner and Marcel Fassler over the No. 3 Corvette of Garcia, Magnussen and Mike Rockenfeller in the season-opening Rolex 24 At Daytona.

Tequila Patrón ESM Takes 36 Hours of Florida: The No. 2 Tequila Patrón ESM team of Derani, Brown, van Overbeek and Sharp became the first team since Doran/Moretti Racing in 1998 to sweep overall race victories in both the Rolex 24 and Mobil 1 Twelve Hours of Sebring Fueled by Fresh From Florida.

For good measure, the No. 4 Corvette team of Milner, Gavin and Fassler also went back-to-back, taking the GTLM win one year after their No. 3 teammates did the same.

Ford GT Wins First: One of the most awe-inspiring race cars in recent memory, the Ford GT, made its debut in the 2016 WeatherTech Championship season-opening Rolex 24 At Daytona, but it wasn’t until Round 4 at Mazda Raceway Laguna Seca when the car’s full potential was realized. Westbrook and Briscoe gave Ford Chip Ganassi Racing and the new program its first victory at Mazda Raceway Laguna Seca, the final tune up prior to the 24 Hours of Le Mans.

Huge Day for IMSA at Le Mans: For the second consecutive year, a full-time WeatherTech Championship team claimed the GTE Pro class victory in the 24 Hours of Le Mans, as Joey Hand, Dirk Mueller and Bourdais teamed up to take the victory in the No. 68 Ford Chip Ganassi Racing Ford GT, coming on the 50th anniversary of the Ford GT40’s 1966 victory at Le Mans.

In fact, the entire GTE Pro podium were WeatherTech Championship regulars, as Fisichella, Toni Vilander and Matteo Malucelli finished second in the Risi Competizione Ferrari ahead of Briscoe, Westbrook and Scott Dixon in the No. 69 Ford GT.

The GTE Am winners also represented IMSA, as Sweedler, Bell and Segal took the class win in the No. 62 Scuderia Corsa Ferrari 458 Italia.

2017

New Era for Prototypes: If the 2016 WeatherTech Championship ushered in a bold new era for GT machines, the 2017 season was revolutionary for Prototype racing with the introduction of new Daytona Prototype international (DPi) and LM P2 race cars.

In the DPi ranks, Cadillac, Nissan and Mazda stepped to the plate in the first year of the format, which enabled major automotive manufacturers to compete in the top class with their own engines and specific bodywork alongside LM P2 race cars using spec Gibson V8 engines and chassis from one of four approved chassis constructors.

New Manufacturers Join GTD Ranks: Continuing the momentum from the first year of GT3 specifications in 2016, three additional manufacturers: Acura, Lexus and Mercedes-AMG entered the GTD fray in 2017. Of the three, Mercedes-AMG was the first to break through with a victory, which came courtesy of Ben Keating, Jeroen Bleekemolen and Mario Farnbacher in the Mobil 1 Twelve Hours of Sebring.

That victory touched off a run of three straight wins for Mercedes before Katherine Legge and Lally gave Acura its first win in the Chevrolet Sports Car Classic at Detroit’s Belle Isle Park before a second straight win in the Sahlen’s Six Hours of The Glen. Lexus, still in search of its first victory, got its first WeatherTech Championship pole position with Sage Karam at the wheel of the No. 14 RC F GT3 at Canadian Tire Motorsport Park.

Penske, Acura Team Up for New DPi: In early July, Acura Motorsports and Team Penske made official what had been rumored for quite some time, that they would be teaming up for a new, two-car DPi effort in the WeatherTech Championship beginning in 2018.

Since then, the first half of the team’s driver lineup – Juan Pablo Montoya and Dane Cameron – were introduced, as was the breathtaking new ARX-05 DPi race car. Testing of the new car is already under way.

Mazda, Joest Shock The World: If the Penske and Acura link-up was heavily rumored, the announcement that Joest Racing and Mazda were joining forces that came the following week was a complete surprise to most.

The Joest team is one of the most successful in prototype racing history, and was looking for an opportunity to re-enter the sport after a 16-year run at the helm of Audi’s LM P1 program came to a close at the end of 2016. Joest found a willing partner in Mazda, which launched its own new DPi program in 2017.

While Mazda Team Joest suspended competition for the remainder of the 2017 WeatherTech Championship in favor of more testing and development, the stage is now set for a titanic battle that will open with the 56th Rolex 24 At Daytona on Jan. 27-28, 2018.